Relatively little is known about differences across countries in changes in medical technology, and the potentially important dynamic implications of these differences for changes in medical expenditures and health outcomes. We will develop a collaborative, global research network to analyze technological change at the "micro" level. We will begin with an analysis of changes in heart attach care, an important health problem for aging populations worldwide, and will gradually expand this focused analysis. Our study has three specific aims: 1. To develop a sustainable global network of collaborating health care researchers with expertise in clinical medicine, economics, epidemiology, and related fields, able to conduct detailed, valid studies with comparable microdata and standardized methods. 2. To conduct a detailed, quantitative analysis of technological change in the treatment of heart attacks in the participating countries, resulting in a series of publications that describe and quantify in detail how technological change for this disease has differed across countries, the economical and regulatory factors influencing these treatment differences, and their consequences for disease outcomes and resource use. 3. To generalize these results, by (a) extending our methods to study the more prevalent but less severe forms of ischemic heart disease, (b) relating our disease-specific, "micro" findings to existing evidence on aggregate "macro" differences in the levels and trends in medical expenditures and health outcomes across countries, and (c) conducting exploratory studies to extend our methods to the analysis of a more chronic illness. Our longitudinal approach and our initial emphasis on a cure, severe illness are likely to make it easier for us to isolate the effects of medical technology from many important but (relatively) stable cross- country differences that confound cross-sectional and "macro" studies. We have conducted extensive preliminary studies to explore the feasibility of this collaborative approach, and their encouraging results have led to this proposal to support the coordination of an international research network on technological change in health care.